Rhododendrons are a must-have for a shade garden. They offer stunning colors and interest all year round, creating a focal point that guests will admire.
Rhododendrons can be grown as bushes, small trees, or even large trees. The ground under your rhododendron will offer moist, damp, rich, slightly acidic soil, and filtered light.
This gives you a great opportunity to choose exotic shade-loving plants to compliment your rhododendrons.
You can decide to have spring flowers, or flowers that bloom in winter when other plants are dormant.
You can go for beautiful foliage that turns orange and yellow in fall.
How about plants that offer luscious berries to attract hummingbirds?
Here are a variety of plants that are ideal to plant under rhododendron trees or bushes. Let’s take a closer look.
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What to plant under rhododendrons
When planting under rhododendrons, you need to choose plants that enjoy shade or filtered light. They should do best in slightly acidic soil that is humus-rich, well-draining, and moist. Some fabulous choices are Astilbes, Primrose, Sweet woodruff, Grape holly, Bleeding heart, and Vinca.
Astilbes love shady and moist conditions. This makes them perfect to plant underneath your rhododendron tree where the light is limited.
Astilbes are loved for their graceful plumes of flowers that are borne on tall stems. The foliage is fern-like and looks attractive all year round.
This lovely plant comes in many varieties. Flowers vary from pink to salmon, white, and apricot.
Astilbe ‘amethyst’ is a popular choice, named for its color that resembles an amethyst stone. It is easy to grow and is tolerant of heavy shade.
Plant in moist soil that is slightly acidic. You can add a layer of mulch to help retain water if your rhododendron does not offer enough shade.
Astilbes attract butterflies, bringing color and movement into your garden.
Another lovely cultivar is Astilbe ‘bridal veil’. It offers luminous ivory-white flowers that become a focal point in a night garden.
2. Primrose (Primula polyantha)
Primrose flowers bloom in early spring and last through the summer. They come in a large choice of colors ranging from white to cream, yellow, orange, red, and pink.
Primrose is hardy and can tolerate shade. That makes it a great choice to plant around the trunk of your small rhododendron tree, where the ground will be moist and shady.
I love the Belarina Cobalt Blue primrose, known for its stunning double purple-blue flowers. They bloom profusely from early to late spring and have a wonderful fragrance that will waft across your garden.
Primrose plants in general love moist well-draining soil. You can add some organic fertilizer if you enjoy tending to your garden. A layer of mulch will also help to retain moisture after planting.
Cut back your primrose after flowering to encourage stronger, new growth in the next season. You can also collect the seeds and store them for the winter for planting in spring.
3. Sweet woodruff (Galium odoratum)
If your rhododendron is growing as a low bush, you need a ground cover that enjoys shade and won’t grow too tall.
Sweet woodruff is a great choice to plant under a rhododendron bush. It thrives in medium to wet soil and loves shade.
This lovely plant has a mat-forming habit and offers pretty white flowers in late spring and summer. The foliage forms a lush carpet of emerald green.
Sweet woodruff has a wonderful scent that intensifies when the foliage is dried.
It is tolerant of most soil types and will do well in the slightly acidic soil under your rhododendron bush.
Is it a fast grower and may need some trimming back from time to time to keep it is shape.
4. Grape holly (Mahonia)
When you look for plants to grow under your rhododendron tree, you should think ‘shade garden’.
Grape holly, also known as Mahonia, is a fabulous choice.
Mahonia is a plant that offers interest all year round, making it even more attractive. In spring it blooms with golden-yellow flowers that attract butterflies and bees.
The leaves emerge as bronze-red and mature to dark glossy green in the summer. When fall arrives, the flowers turn to lovely purple-blue berries that attract birds.
If you enjoy cooking, the berries can be used to make jams or jellies!
Grape holly is easy to care for and thrives in rich, moist, well-draining soil that is slightly acidic.
Check the PH of your soil, a reading of 4.5 to 6.5 is ideal. Grape holly does not have any serious disease or pest issues.
Mahonia does not do well in full sun. That makes it an ideal companion to plant under a rhododendron tree where the light will be filtered.
5. Bleeding heart (Dicentra spectabilis)
When looking for a perfect companion to plant under a rhododendron tree, you need to remember that the soil will be moist and slightly acidic.
Bleeding heart thrives in this type of soil and is a great choice to plant under your rhododendron.
This plant is known for its beautiful blue-green feathery foliage and pink or white flowers. The flowers bloom from late spring into late summer and add a burst of color to your garden.
Bleeding heart loves shade and moist soil. A dense rhododendron tree will give it all the protection it needs from the hot sun.
To get the best flowers, you can fertilize in the spring when the foliage emerges. Choose a time-release fertilizer and dig in some extra organic compost to add nutrients to the soil.
Bleeding heart attracts hummingbirds and butterflies and is also resistant to rabbits and deer.
6. Vinca Periwinkles
Another great choice to add beauty to the space under a low rhododendron bush are Vinca periwinkles.
If your rhododendron bush offers purple flowers, you may want to choose a lovely companion plant that blends in color.
Vinca major, also known as the Big periwinkle, offers showy blue-violet flowers among evergreen glossy leaves. A perfect partner!
Blooming starts in mid-spring and continues through summer into the fall. The stems form long trails that will fill in the space under your rhododendron bush and create a lovely carpet of color.
Vinca does best in part shade, and your rhododendron will provide the protection it needs from the sun.
Best soil conditions should be medium-moisture and well-draining. It is hardy and will thrive in the same type of soil that your rhododendron loves.
To add more variety and interest, plant it together with Vinca major ‘variegata’. This cultivar also offers matching blue-violet flowers, but they have the added attraction of a tinge of ivory-white around the margins.
Get creative with driftwood and fallen branches
Shade gardens transport your mind to woodlands of dense growth and dappled light. Add character to your shade garden by placing driftwood or fallen branches around the base of your rhododendron tree.
This will create an atmospheric spot where you can relax on a hot day and enjoy a cool drink while admiring the wonderful colors and fragrances of your garden.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.